"It's hard to say," Miko Brando, a Jackson friend and son of the late actor Marlon Brando, told "Good Morning America." "Yes, it was an accident. Yes, he took medicine. Yes, the doctors gave him medicine."

"When this happened it just changed the whole atmosphere of the shrine, changed the whole atmosphere, everyone is like, 'Oh god,'" Maze said. "You don't know if he is going to be OK or not."

While Jackson would go on to sell millions more albums and enchant fans around the world, many said that day set the stage for a lifetime of prescription drug abuse.

Nearly a decade later, Jackson admitted in a video statement that he had entered rehab after getting hooked on the medication meant to ease his pain while he healed from the burns.

"This medication was initially prescribed to treat excruciating pain I suffered after recent reconstructive surgery on my scalp," he said in 1993.

Brando said he took Jackson to his doctors' appointments and said the singer did what he was told during his recovery.

"There was nothing out of the ordinary that he did," Brando said. "It was done by the book."

But Brando said he never once saw the evidence of drug abuse that many have pointed to in the two weeks since Jackson died, including track marks on his arms and legs, reportedly from intravenous prescription drug use.

"He was a friend of mine," Brando said. "I didn't inspect him every day."

Investigators removed several prescription drugs from Jackson's rented Holmby Hills mansion after his death, including the powerful sedative propfol, commonly used in operating rooms. Other drugs confiscated included the painkillers OxyContin and Demerol.

As speculation and rumor mounts about Jackson's final days, Brando said he hopes his friend will be remembered for his caring spirit and his devotion to his friends and family.

"If you talk to anyone who knew him, well, they'd tell you the same thing -- he was a really good guy," Brando said. "He was just an extraordinary human being."

Did Pepsi Commercial Accident Start Obsession With Plastic Surgery?

The raw footage shot for the Pepsi commercial was shot on Jan. 27, 1984, at Los Angeles' Shrine Auditorium.

Jackson can be seen on the shoot's sixth take, descending a flight of stairs when the pyrotechnics on stage go off early and engulf the singer's head in flames.

At first Jackson, wearing a sequined shirt, jacket and signature glove -- continues to dance unaware as flames and smoke emanate from his hair. As the fireball grows around his head, he is set upon by members of the crew who tamp out the flames.

In the video, one can easily observe a large red bald spot in the center of Jackson's head after the flames have been extinguished.

Jackson suffered second- and third-degree burns to his scalp and the back of his head, prompting him to begin using and then abusing painkillers, he would later admit.

Us Weekly, which contains pictures of the incident, hits newsstands Friday. The magazine, which has not said how it obtained the Pepsi commercial footage, suggested that the accident kicked off Jackson's obsession with plastic surgery.

The then 25-year-old Jackson was taken by ambulance to Cedars-Sinai Medical Center in Los Angeles.

"Michael is quite shocked. He's fortunate that there were no injuries to his face," Dr. Steve Hoefflin told reporters at the time of the accident. "At this time, I don't think skin grafts are necessary."

Hoefflin is now retired and could not be reached by ABC News.com.

"Within two weeks of the fire, Michael was back on his feet and in good spirits," Jay Coleman, the agent who repped Jackson when he cut the deal with Pepsi, told ABC News.com.

Coleman was not at the shoot but said the accident made front-page news, and the ads were run on the television news weeks before they officially ran as paid spots beginning in February 1984.

Friends, Law Enforcement Confirm Intravenous Drug Use

Friends and associates of Jackson have said they routinely tried to stage interventions to help the singer kick his habit, but they were routinely rebuffed or pushed away.

Friends and family "were very, very scared about these things and we talked together how can we take care of this, but it was very complicated," said Deiter Wiesner, Jackson's former business manager.

A senior law enforcement official confirmed to ABC News that Jackson was "heavily addicted" to the painkiller Demerol and received "daily doses" of OxyContin. His body was found covered in track marks consistent with intravenous drug use.

It has been widely reported that in addition to Demerol and OxyContin, Jackson also abused the anti-anxiety drug Xanax and the antidepressant Zoloft in the months before his death.

In 2002, Jackson was ordered to undergo a medical examination after he failed to show up in a California courtroom in a trial over breach of contract because the pop star said he had a spider bite.

Marc Schaffel, a former associate of Jackson, however, said it was not a spider bite but a problem caused by a broken IV needle.

"He had the IV stuff back then," Schaffel previously told ABC News. "It wasn't a spider bite. It was an IV he pulled out his leg. The needle broke off."

Police have confirmed that several doctors who treated Jackson and are believed to have prescribed him drugs are being questioned or will be questioned.